Ishishi is one of twin boar apprentices journeying alongside the fox protagonist Zorori. He and his twin Noshishi travel with Zorori, joining his schemes and adventures. Their primary role involves assisting Zorori in his quests, though their actions often trigger comedic mishaps or unintended positive outcomes due to clumsiness or misinterpreting plans.

Ishishi exhibits loyalty and devotion to Zorori, consistently following him despite frequent failures. He shares a strong bond with his twin brother Noshishi, their interactions emphasizing synchronized behavior and mutual dependence. A defining characteristic is his gluttony, frequently depicted in scenarios involving food, like overeating or pursuing culinary rewards, which occasionally drives plot developments or comedic situations.

Throughout the series, Ishishi faces numerous perilous situations, including physical dangers like falls from heights, captures, or encounters with antagonists. These events highlight his resilience and the twins' role in inadvertently aiding others despite their initial intentions. For example, Ishishi is separated from the group after falling off a cliff but later reunites with them, demonstrating persistence.

Ishishi occasionally receives individual focus in episodes exploring themes like fortune or personal challenges, such as "Ishishi's Great Great Great Fortune!" where his actions lead to unexpected gains or losses. His character participates in broader story arcs involving family unity, reflecting Zorori's influence in prioritizing familial bonds during their travels.

In various media adaptations, including television series and films, Ishishi remains a consistent presence, contributing to both episodic humor and longer narrative arcs. His design and role maintain continuity across different productions, emphasizing his identity as a loyal, food-motivated companion within the core trio.